Free-wheel ratchet device



May 15, 1928. 1,6?,197

EJ. -C. W'.r HUMFREY i FREE WHEEL RATCHET DEVICE Y F11 d M rch 19, 1.925 5 Sheets-sheet 3" Patented Mey l5, l92,

. ventran stares israel? f ra-traiter crearon] JOHN OIIARLEs wILLIs HUMFREY, or LONDON, ENGLAND; AssIeNon, BY MESNE .as sIeNIanNTs, To 'Inn HUMrnEY-sANDBERG co., LTD., or LONDON, ENeLLINnA BRITISH COMPANY.

FREE-WHEEL RA'rcHE'r DEVICE.

Application filed March 19, 1925, Serial No. 16,847, and in Great Britain 'Maren 24, 1924.

The invention relates to clutch devices 'of' of rotation allowing tree-relative rotation.

between these'parts. Y

' According to theinvention the clutch device vcomprises two coaxial members provided With-conoidal surfaces forming be` v tween them a channel in which are inserted rollers, the axes of whichare skewed. relatively to the axis of t-he said coaxial members. r

In one direction of rotation 'of the shaft the reaction between the driving and driven members gives rise to' a frictional component inthe direction of the axis Ot the shaft which causes a relative axial displacement between the inner and outer conoidal elements and consequently wedges the roll yers betweenthe conoids and connects them rigidly together.v If the rotation is re-A versed, the resolved component causes a relative axial movement between the inner and outer conoi'ds in the opposite direction so that they are 'unclutched The arrange. ment consequently allows` Ian oscillating movement of constant orvariable amplitude ,to be converted into unidirectional rotational movement.

If the rollers are inserted in the race so ,thatltheir axes areinclined lin the opposite direction to the former case, the direction of rotation in which the 'wedging action takes place is also reversed.

Owing to ,the relative inclinationb'etwcen' the axes of the rollers and the axis of the shaft, it is necessary, in order that the roll ers should be Ain contact throughout their whole length 'with the conoidal' surfaces with- Iwhich they engage, that the inner conoid should be slightly concave vand the outer conoid correspondingly convex; that is, the generating'linesr of the' conoids are not straight but slightly curved, the curvature depending upon the inclination of the axes of the rollers.

In a simple construction one conoid' is elastlcally pressedl towards the larger end of the other conoid? f In a modified construction two sets of inner and Aouter conoid'members are arrangedl on the same shaft, eaclrset being provided with rollers, the inclination of the rollers in the'. two sets being in opposite directions andv means are provided by which either set can be brought into or out of action at any time.

Ina further,k modification two sets of in- Lsoy ner and outer conoids are combined to form biconoidal rustums, the smallest diameter of each` conoid being at the centreof the axial length ofthe frustums and one conoid can' be displacedin either'axal direction against an elastic resistance. which allows full freedom of axial movement in the direction of engagement but limits the movement in the direction of disengagement.

In a still urthermodification the axial movement in the direction of'engagement is adjusted so that the clutch will slip when the resistingtorque attains a given value. This arrangement is more especially adapt:-

ed to act as a clutch between two'rotating shafts. y

Other modifications are 'described vand it.v

is understood. that the invention is-not restricted to the examples illustrated and that' various changes may be made in the form' and arrangement of theparts "within the` scope of the invention as set out in the aecompan'ying claims.'4 s

The accompanying drawings. illustrateexinvention.

amples' of constructions according to the 4 'Fig'. 1. is a'n elevat1on, partly in section, of ,i

a clutch with a single row ,of rollers.'

Fig. 2'is a viewsmilar tol Fig. 1 o a reversing clutchin two parts, the rollers'in.

the twoparts being: inclined in rections. v

Fig.v 3 is an elevation, mainly in ,sect-ion,` of

a compound clutch. 1

opposite di- Fig. 1 is an elevation, mainly in section, a modified form of compound clutch.

Fig. 5 is anlele'vation, mainly in section, of a modified form oflreversing clutch.

' modification of a two-part reversing clutch, ed by the source.

the rollers in the two parts being inclined in of known type are mounted loosely on the 'extensions b1, b2 and are adapted to be.4

' Athe figure. In the annular channel betiveen engagement, and in the other direction of material inserted between the base Fig. 6 is a crosssection on the line 6--6 of Fig. 5.V f shaft A and are secured' `to the crank-s El,

Fig. 7 is a sectional `elevation of a further E2 to which an oscillatory `motion is impart- Thrust bearings G1, G2

the same direction.

tubular extensions bi, b surrounding the Figs. 8 and 9 are, respectively,a sectional moved axially in either direction by arms-. i elevation and an end view of a modilication K?, K2 pivoted'respectivelyat'L1, L2.

adapted for clutching two shafts'together. The outer ends 71:1, .7a2 of the said arlns Kil,

Fig. 10 shows a slight modilication 4of the K2 are' provided with internal threads enclutch shown in- Figs. 8 and 9. l

F ig. 1l shows, on an enlarged soale, a which can be rotated in bearings N by a cage for-containing the rollers, and handle O. The threads m1, m2 are'respec- F ig. 12 is a cross-section showing the tively left andright-handed, so that the said cage and roller-s in theirI channel. arms K1,K2 are moved in opposite directions. The same reference letters are used to-'des- A spring I is inserted between the end of ignate similar parts in all the figures. the inner conoid-B1 and an internal shoulder gaging with threads m1, m2 on a spindle M The clutch shown in "Fig, l is adapted to .on the outer conoid C1, and similarly a' convert an oscillating movement.. of YvaryimY spring I2 1s inserted between a collar H3 at;

amplitude .into unidirectionalr rotational movement. f extension b2. The larger ends of cach conoid .A is the shaft-to which rotational motion member are towards the left of the figure is to be imparted, B is an inner conoidal and the rollers D1 are inclined in the opu member secured to the shaft A, Cis anfouter posite directionto the -rollers D2. A circular coaxial conoidal member, the larger ydiamcover plate J-closes the open end of the eters of B and C being' shown on the left of member C2.` y

If the handle D is rotated so that the the members B and C are placed cylindrical thrust bearing G1, and with it thel inner rollers D, theaxes of which are inclined as member B1, is' moved 'to the left and the shown to the common axis of the shaftA and thrust bearing G2-and'inner member B2 to of` the -said conoidal members and lie on an the right, Vthe'outer member C2 and shaft 'A hyperboloid of revolution.- 'Io the outer will be rotated in one direction under the tached to the shaft and the' outer end of the conoid C is attached a crank E which is acoscillatory impulses 'communicated to the tuated by means of a connecting rod F con` crank E2, thel members C1 and B1 being disnected to a source of oscillatory motion. engaged; while if the movement vimparted A thrust bearing G mounted on the shaft to the arms K?, K2 by the handle O is re- A bears on one side g1 against a 'collar H seversed, the shaft A is rotated in-the oppo` cured to theshaft by a pin h and at the other Vsite direction by the oscillatory impulses im'- side g2 again-st a circular spring plate I partedto the crank E1, the conoidal members which presses the member towards the B2and C2 being out of engagement.

left, that is, into-the position in which the In the construction shown in Fig. 3 the lou rollers are jammed between the surfaces of inner conoid Bis slidableon the shaft A the members B and C and transmitthe roand is secured to the oscillating crank E3,

tary movement ofthe latter tothe member thev outer conoid C3 is screw-threaded at c B and shaf't'A.- into a casing P. A colla'rH3 on the said In one direction ofrotatlon of the' outer casing pinned' to the shaft A at k3. A

member C, the counter clockwise direction aS spring I3 is inserted between the thrust bearviewed from the right of the ligure, the axial ing G mounted loosely on the shaftA and component ofthe rictional resistance at the m0011511` R Seem-Qd td the said Shaft by a pin rubbing surfaces of the rollers tends .to forcev r. The springI3 presses` a circular flange Q the outer member to the left, `viz, into closer on the eonoidfagainst a disc S of friction` of the rotation the axial component forces the outcasing P andthe said flange. er member tothe right, in which position no In vone direction of the oscillatory channel in which the rollers are inserted is conoid is urged by the axial component of closed at the larger end of the colloids by a the frictional resistance to wedge within removable cover plate J, a flange j ofwhiCh the outer conoid and at the same time the 1S SGCUI'Od t0 th@ Shaft by SCIBWS it The friction disc S is compressed and tends to channel 1s open at the opposite'end. transmit the drive to the casing P and 1 In the reversing clutch shown in Fig.'` 2, through the casing to the shaft A. vThis efmove-y .motlon 1S transmitted to the shaft. The ment imparted to the crank E3 the mner the parts are duplicated. In this example fect helps to relieve the radial stresses bev the outer conoids C1, C2 are secured to "he tween the inner and outer conoidal members,

shaft A by collars H1', H2 and pins 21.1, h2 and In the opposite direction of the oscillatory the inner conoids 131,132 areprovlded with movement imparted to the crank 3, the

clutched position on the shaft A. .In one' axial component of the frictional forcesA nieves the conoid B3 against thereslstance of the spring I3 into a position in which the members B3 and C are out of engagement.

In the modification shown in'llig. 4, the

inner member B4 is secured to the oscillating crank E4 and is prevented from axialmovement -by the thrust bearings G", G4; theouter member C4 is free to move axially and both members can rotate `freely 1n the undirectioii't-)f rotation the outer member will beforced to the rightagainst the resistance 'both' to," the inner member B4 and to the outer casing P and will rotate the shaft A..

In the'reversing clutch shown in Figs. 5

and 6, the inner .and'outer members B5 andv Cf are formed as biconoidal frustums, the

smallest diameter of their surfaces being at the centre of the axial length. l

The outer member C5 .inserted m ,and secured to a casing P2 and-the inner member 'B5 is secured to a bearing liner T mounted loosely" on ltheshaft A. The rollers tare retained against axial movement at one end by a plate J5 secured' to the casing P-2 by screivs Jz'and at the other end by aplate .l1

which rests against.. an internal shoulder of the said casing.

The inner member is'exte'n'ded on the right beyond the casing P2 and on this extension )I is secured the crank E5. Ball thrust bearings G5 are mounted on the ex- 'tension 7), the dise g? bearing against the crank and the'disc g4 against a nut U.

screw-threaded onthe said extension. The arms K7 spindle M Vand handle` O for op- `erating. the said spindle fare arranged'substantially as described in connection withl Fig.v 2. except the spindle isscreW-threaded inthe bearings N and springs V are inserted onl either. side of the extension lo of the arms K and abut against collars W secured toth'espindleM. y,

lVhen the lever K is displaced to the right, the roller-sl)5 are wedged. between -the inner vand outer conoids so that the shaft A is. r'olill t-ated in a clockwise direction as viewed from the right,l and inthe anticlockwise direction when the lever K is displaced to the left.

The arrangement allows full freedom Iof motion of the biconoid B in either direction of engagement.

The reversing 'clutch shown in Fig. 7 is similarto that shown in Fig. 2 except that therollers DG, D7 are inclined in the same direction andthe larger ends of theconoids B,- B7 and C6, C7 are opposite to one an# other; Only one crank E is required and according to the-position given to the arms K3 either the member C or the member Cl is clutched to the inner member B or B7 when the crank Fi rotates in one direction and is released when the crank rotates inthe reverse direction.

The construction shown in Figsjtl and 9 is also of `the bicouoidal type and is espe- `ciallyadaptedlas a clutch between two rotating shafts A'and A1.

By limiting the axial. movement of the displaeeable member in the direction of engagement, the clutch will slip when the resisting torque attains a certain value. By varying the limits of the axial movement the vclutch `can be'adjustcd to slip at any re- .qu'lred value ofthe torque. Power can stillbe transmitted through the clutch While it 1s slipping', but acertain proportion ot the power of the prime mover is .absorbed 1n the clutch and wasted in heat. AThis' prop,-

erty renders it very useful for starting the driven shaft under load. l

During a period when. the clutch is slipping,v one'or both the elements of the clutch must slip over the surfaces of the rollers, but the rollers. are at the same timel iaused to rotate about their own axes. Thus if the clutch is filled or' fed withy a lubricantthe rotation of the rollers will ensure that the slipping surfaces are.eontinuously changing and are constantly supplied \'ith lubricant.

The 'frictional forces between lubricated surfaces are'a functionof their relative \"e' locities. and after a short period, in which. the forces coupling the members are less than the 'static resisting torque, tend to increase as the relative velocity increases. Thus forv a given lamount of engagement there i'vill be. in dependence `on the resistingtorque offered by the driven member, varying amounts of slip and hence varying ratios ybetween vthe angular velocities ofthev driving and driven shafts. A

`Whcn the .driven member offers a resist# ing torque but slightly' greater than that at which the clutch isset toslip. the amount of slip will besmull, but as this resistance is gradually increased the slip becomes cor.- resp'ondingly'greater until. a'limi't is reached when no motion is transmitted to the driven member.v For easy adjustment of the clutch there is consequently a range of resisting torques through' which combined slip' and drive canA take place.

A is Vthe driving shaft connected to a prime mover and Ais the driven shaft.

The constructlon of the biconoids l and C3.

'of the casingP3 and the thrust bearings G8 las keyed to the shaft A1 by splines a?, thus pervmitting movement of the inner conoid axially of the shaft A but preventing relative rotation between vthe inner conoid and the shaft A1. l f

The arms K1 are pivotedV at z' and their outer extension is formed a ltoothed quadrant- Y engaging `with 'a worm Z on the spindle M2 so as to4 be heldpositively in any required position.

The operation ofl the clutch is as fiollows i 'lVhen the spindle M2 is set`so that the biconoidal-members B8"an d (J8 are in the mean position in which theirsina-llest diameters are'opposite each other` the shafts A and A1 are free to turn relatively to one another in either direction since in this ,position there is no wedging action on the rollers. It the wornt-is operated so as to move the inner menibiwI BS towards the left, the shaft A can drive theshallt A1 in a clockwise direction as viewed in Fig. t). lt

the inner member BS is moved towards the right, the shaft A can drive the shaft A1 in the opposite or anti-clockwise direction; "Ifo every position intowhich the inner meni-` ber B8 is-moved and held ox either side ot its mean position, there corresponds a delinite. resisting torque at which slip will conimence, but,'as explainedabove, it lubrication is applied to the clutch,- a greater torque than that at which slip comniencescan still CIS be transmitted,`the shaft A rei-*olvingvata "higher speed than the shaft A1 and the rollers D8 revolving 'and slipping over one or both conoidal surfaces.- y

In the modification shown in Fig. l0 a spring I is inserted between the shoulder' b3 of the biconoid B and the disc 'g5 ofthe 'thrust bearing G9.

This modification allows the clutch to be used with its norma-l drive and' slip in one direction only (e. g. in the .clutch shown in the clockwisedirec-tion) and the shaft' A1 will` be capablefofl freewheelingl with retitl spect to the shaft A.` That is to say. it the prime mover attached to A be slowed down, A1 can continue to revolve under its own inertia, the axial thrust on the member Pr chan-'ging in direction and tending to ref lease the clutch against the! resistance of the sprintf. The flexibility of the' spring must not be such as to allow the member Bg'to `move past its central position, since it this occurs the shaft A1 will ,tend to drive the shaft A. But this reverse drive can be obtained at any time should it be required, e.

g. for the purpose of using the prime mover as a brake,by moving the arms-K to the right. Since the amount of engagement ot the c lutch when Workingl witlrthe member B9 to the left of itsmeanposition'is now elastically instead of positively controlled, there can. be no adjustment for various degrecs of slip, but direct engagement will trol in the direction of engagement and a flexible controlin 'the direction ot discngagenle'nt, it will act as a unidirectional freev wheel clutch which can be adjusted to give A anydesired degree of slip under various resisting torques. l

^ lVhen provided with bieonoidal surfaces having positive adjustable stops for both directions of axial movement, it will act as Va clutch driving in either directionand 'apable o'l yadjust-ment 'lor slip in either direction. i 'lhen provided with biconoidal surfaces having a positive adjustable stop for one direction of axial movement and a lexible stop -tor the opposite dircction'oi nioven'ient, it willy act as a clutch driving in either direction, capable of slip and of :hice-wheeling in one direction and of direct engaging without slip in the other direction",

vThe rollers may be contained in a sheet metal cage l as shown in Figs. 11 and 12, the

/ cage being closed yat the cnd2 and open. at

1 A clutch comprising Vin combination coaxial conoidal members and rollers, the

axes ot' which are skewed vrelatively to the` common axis of the said members, said rollers being inserted 1n an annular channel provided between the conoidal surfaces of the said members.

2. A clutch comprismg in'comblnation coaxial conoidal members, the opposite surfaces of which are, respectively, concave and convex, and cylindrical rollers, the axes of which arel skewed relatively to the common axis of the said members, said rollers being inserted` in an annular channel provided between the conoidal surfaces of thesaid'nieinbers. 3. Av clutch compris-ing in combination coaxial conoidalmembers and rollers, the axes vof which are skewed relatively to the common axis of the said members, said rollers being. inserted` in an annularchannel provided" between the conoidal ,surfaces of the said members, one 'of said surfaces being concave and the .other convex. f 4. A clutch comprising in combination coaxial conoidal members and rollers, the axes of'which are skewed relatively to the common axisof the said members,` said rollers being inserted in an annular channel provided between `the conoidal surfaces of the said members, one of said conoidal membeis being slidable alongthe saidcom'mon axis. 5. A clutch comprisingin colnbination a shaft, a conoidal lnelnber coaxial witll said shalt and secured thereto, a second conoidal member rotatable about the axis of said shaft and coaxial therewith, the opposite surfaces of saidcolloidal members being, respec-v tively, concave and convex, and rollers, the axes oi' which are inclined to the comlnoll axis of the said conoidal members, inserted in an allnular channel provided between the conoidal surfaces of the said members.

6. A clutch Comprising in combination a biconoidal outer member and a coaxial biconoidal inner member and lrollers, of which the axes are skewed relatively to the coinmon axis -of the said biconoidal members, saidrollers being inserted in a channel providedbetween concave and-.convex surfaces" of the said members..

7. A clutch comprlsin'g'in combination a biconoidal outer member, a biconoidal innei member coaxial therewith, the smallest sec- .biconoidal members.

8.'A clutch comprising iny combination a v, shaft, a biconoidal outer member and a co-y axial biconoidal inner' member, one of said members being secured to the said shaft and the other of saidA members beingslidable axially, and rollers of which the axes are icA skewed relatively to the axis of said shaft,

said-rollers being inserted in an annular channel provided between the adjacent' surf.

faces ofsaid biconoidal members. I 9. -A yclutch comprising 1n combination a shaft, a--bic'onoidal member and a coaxial bi- -conoi'dal-vinner member, the' outer of said members being secured to said shaft'and the inner of said members being movable axially of said shaft, and rollers of which the axes are skewed relatively tothe axis of said shaft,-said rollers being inserted ill an annular channel provided between the adjacent surfaces of said biconoidal members.

10./A clutchcomprising in combination a shaft, a biconoidal Vmember and a coaxial sis.

biconoidal inner member, the outer of said members being secured to saidshaft and the inner of said members being movable axially of-said shaft, rollers of which thel axes are skewed4 relatively to the axis of said shaft',

l channel provided-between the adjacent sursaid rollers being inserted in an annular inner of said members being lnovable axially of said shaft, rollers of which the axes are skewed relatively to the axis of said shaft, said rollers being inserted inv an annular channel provided between the adjacent surfaces of saidbiconoidal members, said illner4 member having an axial extension, means associated with said laxial extension for moving said inner Imember axiallyl ill either' direction, and means for holding said inner member in any required axial position.

l2. A clutch'comprising incombination a sha-lit, 'a biconoidal lmember aild a coaxial biconoidal inner member, the outer of said members being secured to said shaft and the inner of said members being movable axially of said shaft, rollers, the axes of which are skewed relatively to the axis of said shaft, said rollers being linserted in i an annular channel provided between the adjacent sur-v faces of said biconoidal'members, an axial extensionoil said inner member, means associated with said extension for moving said inner member axially in either direction, said last'named means comprising shoulders` on` saidaxialv extension, a pivoted arm engaging between said shouldersand manually biconoidal inner member, the outer of said members being secured to said shaft, and the inner of said members being mov-able vaxially ofsaid shaft, rollers of which the axes are skewed relatively to the axis of said shaft, said rollers being inserted in an ansion for moving said inner member axially' in leitller direction, means for holding said yinner Vmembervin any required position, and

.. In testimony vwhereof I have signed my name to this specification.

JOHN CHARLES WlLLlS HUMFREY.

lis 

